1. It was possible until netease changed the account management interface. Now I don't know if it's still possible, the link in the guide is broken, so you need to contact netease customer service and ask them.
2. Yes to both, look at the stickies in general and technical forum.
3. You can sort it with netease by sending them a scan of the hukou you used. But since you just have an old the9 account, I'm not even sure they would know what to do. Old the9 login and password aren't valid anymore.
4. If I were you I'd start a fresh new char(since you sound like needing at least a month of customer service with netease). The new dungeon finder let's you enjoy leveling through dungeons from lv 15. We got WOTLK in China recently and there's only a good 8months to go until with see cataclysm(based on rumors). There are ppl already playing cataclysm on taiwan servers too.
I guess that's all